This is the next in a series that look at every position on offense and defense with training camp approaching. Our fifth look is at offensive tackle.

Returning starters: Kelvin Beachum and Marcus Gilbert. Beachum stabilized left tackle after Mike Adams floundered there in the first four games last season, and it is his position to lose heading into training camp. Gilbert started every game last season at right tackle and was the only Steelers’ offensive lineman to start every game in 2013.

On the bubble: Guy Whimper. A lot would have to happen for the 6-foot-5, 318-pounder not to make the team. Whimper proved to be a dependable reserve last season, and he has the flexibility to play inside as well. Whimper could be competing with rookie Wesley Johnson, a fifth-round draft pick, if the Steelers keep only eight offensive linemen when they finalize their 53-man roster.

By the numbers: Ben Roethlisberger got sacked 24 times in the 11 games that Beachum started at left tackle last season. He was dropped 18 times in the five games that Adams started at the position.

Did you know: The Steelers averaged 124 rushing yards in the six games that Adams started at right tackle as a rookie in 2012. Their season rushing average was 96.1 yards.

Quotable: “I’m not a big-frame guy. I never have been. I’m not a 320- or 330-type of offensive lineman. I know I have to keep my weight down, keep my body fat down, stay lean, stay fast, use technique. That’s something that I’ve used since college and have to continue to fine-tune that. I think with the addition of Coach [Mike] Munchak, technique is really going to be a thing that he focuses on and makes sure that we do a good job of.” -- Beachum

Outlook: It will be interesting to see where Adams gets to compete for a starting job at training camp. Beachum is not a prototypical left tackle but the 2012 seventh-round pick got the job done there last season. Adams has played considerably better at right tackle and Gilbert is going into the final year of his contract. Whoever is the odd man out at tackle as far as starting should give the Steelers a quality reserve there.

This is the next in a series that previews every position on offense and defense with training camp approaching. Our seventh look is at center.

Returning starter: Maurkice Pouncey. The three-time Pro Bowler returns after missing all but eight snaps last season because of a torn ACL. Pouncey looked terrific during offseason practices, and the Steelers have already rewarded him with a five-year contract extension.

Key loss: Fernando Velasco. He would have gotten a lot of votes for most unsung Steelers player last season after taking over for the injured Pouncey in the second game of the season. Velasco started 11 games at center before rupturing his Achilles tendon. The shame of that injury is Velasco would have likely parlayed his work with the Steelers into a multi-year contract and starting job elsewhere. He remains unsigned as he works his way back from the injury.

On the bubble: David Snow. The Texas product signed with the Steelers early last December to provide depth, but he didn’t dress in any of their last four games. Snow has to beat out Cody Wallace, who appears to be pretty entrenched as Pouncey’s primary backup who can also play guard.

By the numbers: Pouncey played in 45 of 48 regular-season games from 2010-12, starting all of them, before missing most of last season with a knee injury.

Did you know? Wallace is with his sixth NFL organization. A fourth-round pick by the 49ers in 2008, Wallace had never started an NFL game before taking over at center for the final four contests in 2013 and helping the Steelers average 115.3 rushing yards.

Quotable: “These guys really rally around him. They really are encouraged by watching the way he worked out after being hurt in the opener. How he’s come back and all the time he’s put in this building to get the chance to be part of these workouts again, I’m really excited where he’s at, and I’m really excited as a line coach when you know you have a guy like him locked up for a long term.” – offensive line coach Mike Munchak on Pouncey.

Outlook: Velasco and Wallace did an admirable job of holding down the position last season, but Pouncey is one of the top centers in the NFL when healthy. His return should provide a big boost to a unit that allowed just seven sacks in the Steelers' final seven games in 2013 and came together in the second half of the season. Pouncey still has growth potential and should only get better while working with Munchak.

This is the next in a series that previews every position on offense and defense with training camp approaching. Our sixth look is at guard.

Returning starters: David DeCastro and Ramon Foster. The Steelers are in good shape here as DeCastro has emerged as a Pro Bowl caliber-player at right guard, and the steady Foster has already made 57 career starts and is just 28 years old.

New faces: Wesley Johnson, Will Sutton and Chris Elkins. The Steelers took Johnson with the second of their two fifth-round draft picks and signed Sutton and Elkins as undrafted free agents.

On the bubble: Johnson. The Vanderbilt product can play anywhere along the offensive line, and the Steelers should try to groom him for the all-purpose role that Kelvin Beachum played up front before becoming the team’s starting left tackle. Johnson's versatility will be the key if he makes the 53-man roster.

By the numbers: The Steelers have had just three guards selected to the Pro Bowl since 1975: Carlton Haselrig (1992), Duval Love (1994) and Alan Faneca (2001-07).

Did you know: DeCastro’s overall blocking grade on 96.88 percent as a senior at Stanford was the highest score recorded by a Pac 12 offensive lineman since the conference started tracking grades for offensive linemen in 1985.

Quotable: “It’s nothing right now, and I say that in the sense that [the group’s potential] has been talked about the last few years. The talent is there, but if we come out here and [falter] we’ll be saying the same thing next year. You can’t just say because we have the high-round talent or guys that have experience, that it’s supposed to be special. We’ve got to make it that way.” -- Foster on the Steelers’ offensive line.

Outlook: The Steelers appear to be pretty set at guard with Cody Wallace, providing depth and DeCastro and Foster locked in as the starters. There is no reason to think that DeCastro won’t develop into a perennial Pro Bowler as Faneca, another first-round pick, did in the 2000s.